OBJECTIVES: 1. To study the biosynthesis of slow reacting substance of anaphylaxis (SRS-A), its regulation and modification in cultured rat basophilic leukemia cells (RBL-1) and purified mast cells. a) to further investigate the role of arachidonic acid metabolism in SRS-A formation; b) to characterize the chemical, chromatographic, and biological properties of intermediates in the synthesis of SRS-A; c) to study the subcellular localization, properties and regulation of the enzyme(s) involved in biosynthesis of SRS-A. 2. To determine the distinct biological properties of SRS-A and to pharmacologically manipulate its action in isolated perfused lung, heart, and kidney preparations and a variety of vascular smooth muscles. 3. To raise specific antibodies to SRS-A to be used to develop a radioimmunoassay for SRS-A and to specifically inhibit the action of endogenous SRS-A.